Piston peening machine



y 19429 D. D. ROBERTSON 2,288,842

PISTON PEENING MACHINE Original Filed Oct. 8, 1936 6 Sheets-Sheet l 1N VEN TOR.

lfi ATTORN July 7, 1942. D. D. ROBERTSON PISTON PEENING MACHINE Original Filed Oct. 8, 1936 6 Sheets-Sheet 2 y 1942. o. D. ROBERTSON 2,233,842

PISTON PEENING MACHINE Original Filed Oct. 8, 1936 6 Sheets-Sheet 3 (Br W i j i ATTOK Vif July 7, 19 2- D. 0. ROBERTSON 2,288,842

PISTON PEENING MACHINE Original Filed Oct. 8, 1936 6 Sheets-Sheet 4 j\ r .rm 2 30 26 73 72 INVENTOR.

July 7, 1942. RQBERTSON 2,288,842

PISTON PEENING MACHINE Original Filed Oct. 8, 1936. 6 Sheets-Sheet 5 I I v BY M M 1J4! ATTORNEY.

July 7, 1942. D. D. ROBERTSON PISTON PEENING MACHINE Original Filed Oct. 8, 1936 6 Sheets-Sheet 6 iii QRNEY.

Patented July 7, 1942 PISTON PEENING MACHINE I Delmar D. Robertson, Toledo, Ohio, asslgnor to Wilkening Manufacturing Company, Philadelphia, Pa., a corporation of Delaware Original application October 8, 1938, Serial No. 104,637. Divided and this application July 1,

1939, Serial No. 282,560

2 Claims.

The present invention relates to certain new and useful improvements in piston peening machines, and it relates more particularly to a trip hammer mechanism of a size and proportions corresponding to the size and proportions of pistons commonly used in automobile engines, whereby a rapid series of hammer strokes can be applied to the inside surface of the skirt-wall of a piston so as to re-shape the same, as for instance to expand the same, as may be desired, to conform such piston skirt to the cylinder of the engine.

This application is a division of parent application Serial No. 104,637 filed October 8, 1936.

In the accompanying drawings, in which like reference characters indicate like parts,

Figure 1 represents a perspective view of a piston peening machine embodying the present invention;

Figure 2 represents a front elevational view of the piston peening machine embodying the present invention.

Figure 3 represents a left side elevational view of the same.

Figure 4 represents a right side elevational view of the same.

Figure 5 represents a top plan view of the same.

Figure 6 represents a section on line 66 of Figure 2.

Figure 7 represents a side elevational view of the trip hammer mechanism, with some of the outer housing partly broken away around the trip hammer mechanism, to expose to view some of said mechanism and with part of the pedestal omitted so as to shorten the view.

Figure 8 represents a front elevational view of the trip hammer mechanism, with the hammerarm broken away so as to expose to view the trip mechanism behind the same, and with the anvil shank also broken away; shown on a scale somewhat larger than the scale used in Figure 7, and

with the lower, generally upright supporting pedestal entirely omitted from this view.

Figure 9 represents a perspective view of some of the operative elements of the hammer trip mechanism;

Figure 10 represents a section on line Iii-l0 of Figure 11;

Figure 11 represents a section on line |Ill of Figure 8;

Figure 12 represents a section on line l2--i2 of Figure 11;

Figure 13 represents a sectional view on line l3-l3 of Figure 11;

Figure 14 represents a side elevational view of the adjustable anvil;

Figure 15 represents asection on line l5l5 of Figure 14.

Within any suitable housing or supporting framework, designated generally by the numeral 29, a generally horizontal shaft 2| is suitably journalled, as for instance, in the bearings 22 and 23 on the opposite sides of the housing or supporting frame work. The bearings 22 and 23 may be of any suitable construction, as for instance, the split and capped bearings indicated generally in Figures 7, 8 and 11. On the shaft 2| any suitable pulley 24 is idly mounted, as for instance, the generally V-shaped pulley indicated particularly in Figures 8 and 10, so as to rotate freely upon the shaft. Upon the pulley 24 any suitable annular and concentric driving clutch member 25 may be provided, as for instance, that indicated more particularly in Figure 10, having the pair of oppositely inclined, conical frictional surfaces 26 and 21.

A driven clutch member 28 is mounted upon the shaft 2| adjacent the driving clutch member 25, but keyed thereto by means of the key 29 and slidable axially on said shaft 2! and key 29, and having a suitable annular concentric channel 39 in registration with, and in operative juxtaposition to the driving clutch member 25, and having corresponding conical friction surfaces 3| and 32 adapted for frictional engagement with the surfaces 26 and 21.

Behind the housing 20, and carried by the table 33 (which also carries the housing 20), any suit- ,able electric motor 34 is mounted, with its axis parallel to the axis of the shaft 2|, and with a V-pulley 35 on the shaft thereof, in alignment with the pulley 24. A suitable V-belt 36 is placed over the motor pulley 35 and clutch pulley 24, so as operatively to interconnect the same. By running the motor constantly and then from time to time pressing the driven clutch member 23 into frictional engagement with the driving clutch member 25 in the direction of the arrow 31, the shaft 2| may be rotated at a predetermined speed;--the shaft 2i remaining stationary when the clutch member 23 is in the retracted position indicated in Figure 10. In the hub-like portion 38 of the driven clutch member 28, an annular groove 39 is provided. A pivot bracket 40 is carried inside the frame or housing 20, and to the pivot bracket 40 the L-shaped arm ii is pivotally secured at 42. The upwardly extending portion 43 of the L-shaped arm ii is bifurcated into a fork-like terminal which straddles the so that the driven clutch member 28 may be.

rotated freely in relation to the fork 43, and so that by oscillating the fork 43 about the pivot 42, the driven clutch member 28 may be guided into and out of operative engagement with the driving clutch member 25, in order to impart rotary motion to the shaft 2|, or to deprive said shaft of such rotary motion, at the will of the operator.

A helical tension spring 46 may be operatively interposed between the fork 43 and a suitable anchorage 41 carried by the housing 28, thereby normally to tend to retract the driven clutch member 28 from the driving clutch member 25. A suitable pull rod or operating rod 48 may be linked to the arm 4|--43 at the point 49, and may be extended downwardly to a suitable opening 58 in the bottom of the housing 28, and down through the supporting pedestal to a foot treadle 52 pivoted at 53, whereby the clutch may be brought into operative engagement by depressing the treadle 52 with the foot.

Upon the shaft 2| a trip cam member 514 is fixedly secured by the key 55 intermediate the hub thereof and the shaft 2|; the trip cam member 54 having one or more circumferentially distributed eccentric rises 58. In the particular illustration shown, there are two cam rises 56 in diametrically opposite positions, although this number may be varied according to the speed of the shaft 2| and the frequency of blows or strokes desired.

Adjacent the trip cam 54 a cone 51 is mounted on the shaft 2 free to move axially thereon, and either rotationally free with respect to the shaft or rotationally keyed thereto. In the particular illustration shown, the cone 51 is free both for axial sliding movement on the shaft 2|, as well as rotationally free. In the hub portion 58 of the cone 51, an annular groove 59 is provided for receiving the inwardly projecting pins 68 of the cone-operating fork 6|. The cone-operating fork 6| is also pivoted to the pivot bracket 48 at the point 42, and is also generally toe-shaped, as indicated in Figure 8. An operating rod 62 is suitably linked to the fork arm 6| at the point 53, and extends downwardly through a suitable opening 64 at the bottom of the housing 28 and down through the table 33 and then through the open under end of the hollow pedestal 5| to a foot treadle 65 pivoted at 66, whereby the cone 51 may be moved axially on the shaft 2| by foot operation. A helical tension spring 61 serves normally to retract the cone 51, so that the depression of the foot will move the cone towards the trip cam 54.

In a pair of upper spaced pivot brackets 68, a pivot pin 69 is secured. On the pivot pin 69 a hammer-arm hub 18 is journalled so as to be free to oscillate rotationally about the said pivot pin 69. From the hammer arm hub 18, the hammer arm 1| extends outwardly and downwardly as indicated in Figures 1, 5 and 4, and the trip arm 12 extends downwardly into alignment with the trip cam 54 and cone 51. The hammer arm 1| and trip arm 12 have been placed in generally the same vertical plane, although these two members may be spaced from each other in an axial direction any suitable distance upon the same hub or upon a connecting shaft through which they may be fixedly inter-connected.

To the trip arm 12, a cam follower shoe 13 is secured, as for instance by means of screws 14. The cam follower shoe 13 is provided with a flat surface 15, in alignment with the cam rises or lifts 56, which is adapted to ride on said lifts 56 and then to be released or dropped off the end of the lift as the same rotates in the direction of the arrow 16. The shoe 13 is also provided with an inclined toe 11, having substantially the same inclination as the surface of the cone 51 and in operative. juxtaposition to said cone, whereby the contact between said toe 11 and cone 51 will establish the limiting position of the trip arm 12, and hence of the hammer arm 1| on the operative stroke.

A helical tension spring 18, or any other suitable spring such as a leaf spring, cantilever type or beam type, may be operatively interposed between the trip arm 12 or the hammer arm 1| at some stationary part of the frame work or housing. In the particular illustration shown, the helical tension spring is interposedbetween the anchorage 19 on the trip arm and an adjustable anchorage 88 adjustably carried in the back wall 8| of the frame work or housing. The adjustable anchorage 88 is in the form of a screw which is extended freely through an opening 82 in the housing wall 8| and is screw-threadedlyengaged by the nut 83 joumaled in the outer enlarged opening 84 in the housing wall and having an external knurled or other suitable enlarged flange or ring 85 for manual engagement in order to tighten or loosen the spring 18. The adjustable screw anchorage 88 may also be provided with a longitudinal key-way 86, into which the smooth reduced end 61 of a set-screw 88 is adapted to project, so as to prevent the screw anchorage 88 from turning as the nut 83 is rotated thereon. The nut 83 may also be provided with a slight annular groove 89 through which a tangential pin 98 may be extended through that portion of the housing so as to lock the nut 83 axially in the enlarged opening 84, without however interfering with its rotation.

If desired, additional means may be provided for limiting the hammering motion of the hammer 1|, as for instance the set-screw 9|, screwthreadedly-extended through the portion 92 of the housing, as indicated at 93, and having its inner-most end 94 in alignment with the triparm 12, so as to act as a stop for said trip-arm and also for the hammer arm 1|. The outer end of the screw 9| may be provided with a knurled head 95, so that it may be manually adjusted, and may also be-provided with a knurled or other suitable lock nut 98, whereby it may be locked in any adjustable position, as indicatedparticularly in Figure 11.

To the basal portion 91 0f the housing 28, the anvil holder 98 is suitably secured as, for instance, by the bolts 99.

The anvil holder 98 is provided with the bottom and top flat guide surfaces I88 and IN, on the laterally projecting portions I82 and I83, respectively, carried by the upright portion I84. The surfaces I88 and |8| are parallel with each other and between them a slide I85 is adjustably mounted, as indicated in Figures 8, 11 and 14.

A loose clamping plate I86 is disposed between,

the laterally' projecting portions I82 and I83 and serves as the fourth side of a more or less fully enclosed guide passageway for the slide I85. The wall I84 is provided with a screw-threaded opening I81 at approximately the center thereof, with an outwardly projecting boss I88 for reinforcing said wall and increasing the length of the screw-threaded hole, and a bolt I06 is extended through a corresponding and registering opening H in the clamping plate I06 of the anvil holder and is threaded into the wall I04 so as to permit the tightening of the plate I06 against the slide I05, thereby to lock the slide in any predetermined position. The slide I05 is in turn provided with an elongated opening or slot III which clears the bolt I00, so that the bolt may extend through the slide without it interfering with the movement thereof within the necessary limits of such movements.

The slide I05 is provided with a downwardly projecting portion II2, having 'a threaded hole III axially aligned with another hole I I4 in the lower central portion of anvil holder 68. An adjustment screw II5 passes through and is free to rotate within the hole H4 in the anvil holder. A portion of said adjustment screw II5 extends beyond the hole H4 and is threaded so as threadedly to engage in the internally threaded hole H3 in the slide I05. The adjustment screw II5 may be constrained from axial movement relative to anvil holder 96 by means of an integral circumferential collar II6 which is restrained on one side by shoulder III of anvil holder 96, and on the other side by a tangential pin II8, passing through the anvil holder 98. In order to rotate the pin II5, an externalknurled flange or other suitably enlarged flange or ring or knob I I6 may be fastened to the protruding end of the adjustment screw II5 opposite the threaded end thereof, by means of a pin I20 or by any other suitable means.

The upper end of the anvil slide I05 carries an anvil table I2I preferably formed integrally therewith, and the anvil table is recessed slightly at a point in registration with the hammer point I25 as indicated at I22, and into said recess a small anvil plate I23 is inserted, held in place against lateral displacement by suitable screws I24. The anvil plate I23 may be of a specially hard metal or a specially tough metal, as for instance, some special grade of tool steel or other suitable steel or alloyed steel, while the anvil table I2I and slide I05 may be made of a steel forging or the like.

Instead of providing an adjustable work holder of any of the conventional types represented by the vise and other adjustable work holders commonly employed (wherein a pair of generally parallel jaws or work retainers are adjustable in relation to each other or adapted to open or close by rectilinear motion in relation to each other or by angular or pivotal motion) in the piston peening machine of the present invention only a stationary, rigid and non-adjustable work holder is provided comprising merely a pair of parallel, stationary and fixedly mounted guide rails in pre-determined and fixed spaced relation to each other and preferably in the form of freely revolvable rollers, so as to minimize the frictional resistance of these guide rails when it is desired to give the work a slight rotary motion while resting between these guide rails. The rollerlike guide rails I34, preferably provided at their ends with short trunnions I33 of reduced diameter, are rotatably supported in the fixed and stationary terminal rail brackets or roller brackets I26 and I30. The lower and upper rail-supporting or roll-supporting brackets I26 and I30 are suitably .and stationarily secured to any stationary part of the machine, as, for instance, the stationary anvil holder 36, by bolts or screws I29 and I32, and dowels Ill. The lower railwith its pair of side supporting arms I21, or may be separately formed and fixedly secured thereto by means of rivets I20 or the like.

The distance between the pair of parallel roller-like guide rails I34 is somewhat less than the smallest diameter of piston for which the machine is intended to be used, so that any piston may be rested on these guide rails without falling through between them or without passing completely between them. After the piston to be worked upon has been placed or rested upon the guide rails with the open end of the piston upwardly, the anvil I2I is brought forward until the anvil plate I23 just touches the piston wall. This is done by merely loosening the bolt I09 sufliciently to permit a sliding movement of the anvil slide I05 and then turning the knurled knob H9 until the contact is made and then tightening the bolt I03 again.

A shaft I36 extends below, and is secured at its upper end to the underside of the lower rail supporting bracket I26. Along shaft I36 may be adiustably mounted a holding arm I36, as indicated in Figure 11; said arm being held in place by a screw I31 having a suitable knurled head. The arm I36 is preferably provided with a ball shaped contact head I33 which may contact the closed end of the piston designated generally by the numeral I39 and indicated in dotted lines in Figure 11.

I The hammer point I25 may also be of special hard or tough steel and is preferably inserted into the end of the hammer arm H as indicated in Figure 11. This hammer point may be either screw-threadedly inserted or may be inserted into a plain hole .of smaller diameter than the head of the hammer point and then held in place by a lateral set screw.

As indicated particularly in Figure 1, the pedestal 6| is generally hollow and open at its upper end, and to the upper flange I6I thereof the table 33 is securedby means of the bolts I62. To the table 33 in turn the hammer housing 20 is secured by means of the bolts I63.

A suitable sheet metal cover I64 of suitable contour is then extended over the housing 20, as well as over the motor 34 behind said housing so as to completely enclose all the operative mechanism.

The height of the pedestal 5| is preferably 'such as to permit the operator to sit in front of the machine on an ordinary chair with his feet on the foot treadles and with the anvil more or less approximately at table height so as to permit the operator to manipulate the piston on the anvil with his hands and also-to have his eyes focussed on the hammering zone inside the piston while the operator is in such seated position.

The table 33 is preferably extended laterally on either side of the hammer housing 20 and on either side of the sheet metal casing I64 so as to provide horizontal table areas I65 and I66 upon which the work in progress may be placed.

If desired, an abrasive wheel such as an emery wheel I61 may be mounted on one of the ends, as for instance, on the right end of the shaft of the motor 34 or upon a suitable extension thereof, on which the piston may be trimmed by grinding if necessary. The emery or carborundum or abrasive wheel I61 is of the face-grinding type as indicated in Figure 1. If desired, the table 33 may be elevated slightly as at I60 adjacent the face of the abrasive wheel I8! so that the piston may be rested thereon for grinding;- the upper surface'l69 being preferably flat and horizontal and at a right angle to the face of the abrasive wheel I6'I.

If desired, another shelf III) may also be provided on the pedestal somewhat beneath the I table 33, upon which additional work in progress vided in registration with opening I58 in sidewall I59 of housing 20 for access to the bolt head I60 of bolt I09. Side openings I16 and I'll at the base of the pedestal are provided for the passage of the foot control means heretofore described. In the frontwall of the sheet-metal cover I64, a generally vertical opening I18 is provided sufflcient to clear the hammer-arm II.

The. present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered, in all respects as illustrative and not restrictive, reference being had to the appended claims rather than to the foregoing description to indicate the scope of the invention.

Having thus described the invention, what is hereby claimed as new and desired to be secured by Letters Patent, is:

1. A trip hammer for pistons including a main shaft, an idle pulley mounted thereon permanently connected with an electric motor, an axially movable clutch member mounted upon said shaft adjacent said idle pulley and keyed to said shaft and adapted to establish frictional engagement [between said idle pulley and said on, means arranged generally continuously to ro-.

tate said idler pulley, a clutch member keyed to said shaft alongside said idler pulley and axially slidable along said shaft into and out of frictional engagement with said idler pulley, a

hammer arm pivotable about an axis parallelto the axis of said main shaft, a trip arm fixedly connected with said hammer arm and having its end in proximity to said main shaft, spring means constantly urging the end of said trip arm towards said main shaft, cam means fixedly mounted on said main shaft for tripping said trip arm, an adjustment cone slidably mounted on said main shaft in proximity to said cam means, follower means carried by said trip arm having one portion riding said cam means and another portion'riding the proximately-disposed adjustment cone, and separate control means extending from said clutch member and from said cone, respectively, for shifting them axially along said main shaft.

' DELMAR D. ROBERTSON. 

